Dynamic mechanical loading of engineered cartilage cells has been shown to improve mechanical properties of cells. Despite the fundamental importance of mechanical properties for the function of tissue-engineered cartilage, the ability to characterize and assess such mechanical properties in vitro lags far behind the sophistication of characterizing biological aspects of tissue development in response to mechano-stimulation. This may hinder systematic optimization of functional tissue engineering driven by mechanical function criteria, such as the expression of non-linear and viscoelastic behavior vital for the function of native articular cartilage.
Most existing systems for dynamic loading of tissue cultures in vitro (i.e., mechano-active bioreactors) do not enable measurement of tissue mechanical properties in vitro. Those tissue culture systems that do allow for assessment of some tissue mechanical properties in vitro apply loading in displacement control and not force control. Such loading in displacement control causes inherent limitations for assessment of tissue mechanical properties.
Conversely, systems for material testing of tissues under dynamic loading exist. However, these systems do not accommodate tissue cultures in culture dishes, and typically do not provide controlled loading and desired mechanical property assessment in the same apparatus. As such, they do not provide a practical culture environment typically required for cartilage tissue culture and experimentation.